cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-8 of 8 results.

A050926 Binary representation of A007908(n).

Original entry on oeis.org

1, 1100, 1111011, 10011010010, 11000000111001, 11110001001000000, 100101101011010000111, 101111000110000101001110, 111010110111100110100010101, 1011011111110111000001110000111110
Offset: 1

Views

Author

Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Dec 30 1999

Keywords

Links

Crossrefs

Cf. A007908, A097580, A097582, A097583.
Cf. A007088.

Formula

a(n) = A007088(A007908(n)). - Seiichi Manyama, Apr 23 2022

A097580 Base 3 representation of the concatenation of the first n numbers with the most significant digits first.

Original entry on oeis.org

1, 110, 11120, 1200201, 121221020, 20021100110, 2022201111201, 212020020002100, 22121022020212200, 1011212101120110200001, 11101000122011021220211010, 121012010100112220022220220120
Offset: 1

Views

Author

Cino Hilliard, Aug 29 2004

Keywords

Comments

Consider numbers of the form 1, 12, 123, 1234, ..., N. Find the highest power of 3^p such that 3^p <= N. Then p = [log(N)/log(3)] and for 0 <= qi <= 2 [N/3^p] = q1 + r1 [r1/3^(p-1)] = q2 + r2 ........................ rp/3^1 = qp + rp+1 rp+1/3^0 = qp+1 0 For N = 1234, p = [log(1234)/log(3)] = 6 division quot rem 1234/3^6 = 1 505 505/3^5 = 2 19 19/3^4 = 0 19 19/3^3 = 0 19 19/3^2 = 2 1 1/3^1 = 0 1 1/3^0 = 1 0 The sequence of quotients, top down, form the entry in the table for 1234. Obviously this algorithm works for any N.

Examples

			The 4th concatenation of the integers > 0 is 1234. base(10,3,1234) = 1200201 the 4th entry in the table.

Links

Crossrefs

Cf. A007908, A050926, A097582, A097583.
Cf. A007089.

Programs

  • Mathematica
    Table[FromDigits[IntegerDigits[FromDigits[Flatten[Table[ IntegerDigits[n],{n,i}]]],3]],{i,12}] (* Harvey P. Dale, May 23 2011 *)

Formula

a(n) = A007089(A007908(n)). - Seiichi Manyama, Apr 23 2022

A097583 Octal representation of the concatenation of the first n decimal numbers with the most significant digits first.

Original entry on oeis.org

1, 14, 173, 2322, 30071, 361100, 4553207, 57060516, 726746425, 133767016076, 21756176604103, 3404420603635070, 536705213574536755, 104420417226264430242, 15305164771273206577527
Offset: 1

Views

Author

Cino Hilliard, Aug 29 2004

Keywords

Examples

			1234 decimal is 2322 octal the 4th entry in the table.

Links

Crossrefs

Cf. A007908, A050926, A097580, A097582.
Cf. A007094.

Programs

  • Mathematica
    Table[FromDigits[IntegerDigits[FromDigits[Flatten[IntegerDigits/@ Range[ n]]],8]],{n,20}] (* Harvey P. Dale, Aug 11 2021 *)

Formula

a(n) = A007094(A007908(n)). - Seiichi Manyama, Apr 23 2022

A353115 Base-7 representation of A000422(n).

Original entry on oeis.org

1, 30, 636, 15412, 314241, 5363433, 122026543, 2113022646, 33321631443, 536166343420, 143160211151106, 34336660114345260, 11025520662032415631, 2346534662055361221261, 535040660151320030232114, 150206616416004416563301662
Offset: 1

Views

Author

Seiichi Manyama, Apr 24 2022

Keywords

Crossrefs

Cf. A000422, A353110, A353111, A353112, A353113, A353114, A353116, A353117.
Cf. A007093, A097582.

Programs

  • Ruby
    def A(k, n)
  (1..n).map{|i| (1..i).to_a.reverse.join.to_i.to_s(k).to_i}
end
p A(7, 20)

Formula

a(n) = A007093(A000422(n)).

A353104 Base-4 representation of A007908(n).

Original entry on oeis.org

1, 30, 1323, 103102, 3000321, 132021000, 10231122013, 233012011032, 13112330310111, 23133313001300332, 101331301332300201003, 130010202012003303220320, 223313011101131330223313231, 1010202010033102302310203002202
Offset: 1

Views

Author

Seiichi Manyama, Apr 23 2022

Keywords

Links

Crossrefs

Cf. A007908, A050926, A097580, A097582, A097583, A353105, A353106, A353107.
Cf. A007090.

Programs

  • Ruby
    def A(k, n)
  (1..n).map{|i| (1..i).to_a.join.to_i.to_s(k).to_i}
end
p A(4, 20)

Formula

a(n) = A007090(A007908(n)).

A353105 Base-5 representation of A007908(n).

Original entry on oeis.org

1, 22, 443, 14414, 343340, 12422311, 304001232, 11130030203, 223101104124, 200240443211120, 130211343340003021, 112140204001002213422, 100421133100401442024323, 40324014240311242321340224, 31241112311230113034201201130
Offset: 1

Views

Author

Seiichi Manyama, Apr 23 2022

Keywords

Links

Crossrefs

Cf. A007908, A050926, A097580, A097582, A097583, A353104, A353106, A353107.
Cf. A007091.

Programs

  • Ruby
    def A(k, n)
  (1..n).map{|i| (1..i).to_a.join.to_i.to_s(k).to_i}
end
p A(5, 20)

Formula

a(n) = A007091(A007908(n)).

A353106 Base-6 representation of A007908(n).

Original entry on oeis.org

1, 20, 323, 5414, 133053, 2351320, 42243331, 1120335530, 20130035113, 5401014424514, 2343052550252003, 1114323133240053240, 321321022332303252301, 132140014431255340214310, 42015444551405453142112503
Offset: 1

Views

Author

Seiichi Manyama, Apr 23 2022

Keywords

Links

Crossrefs

Cf. A007908, A050926, A097580, A097582, A097583, A353104, A353105, A353107.
Cf. A007092.

Programs

  • Ruby
    def A(k, n)
  (1..n).map{|i| (1..i).to_a.join.to_i.to_s(k).to_i}
end
p A(6, 20)

Formula

a(n) = A007092(A007908(n)).

A353107 Base-9 representation of A007908(n).

Original entry on oeis.org

1, 13, 146, 1621, 17836, 207313, 2281451, 25206070, 277266780, 34771513601, 4330564256733, 535110486286816, 65858371163036861, 8202185121837583406, 1113465620754570813253, 134741562223525280514741, 16425841240157671153405780
Offset: 1

Views

Author

Seiichi Manyama, Apr 23 2022

Keywords

Links

Crossrefs

Cf. A007908, A050926, A097580, A097582, A097583, A353104, A353105, A353106.
Cf. A007095.

Programs

  • Ruby
    def A(k, n)
  (1..n).map{|i| (1..i).to_a.join.to_i.to_s(k).to_i}
end
p A(9, 20)

Formula

a(n) = A007095(A007908(n)).
Showing 1-8 of 8 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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